Multilayer sheet comprising a protective polyurethane layer

Abstract

The invention relates to a multi-layer sheet for use as a decorative protective film on a door or window post of a vehicle. The multi-layer sheet comprises (i) a polymeric film having a thickness of not more than 150μ and that is formed from an ionomer of an olefin-vinyl carboxylic acid copolymer, (ii) on a first side of the polymeric film a cross-linked polyurethane layer comprising the crosslinking reaction product of a polyurethane containing acid groups and a crosslinker and (iii) on a second side of the polymeric film opposite to the first side, an adhesive layer.

1 . Multi-layer sheet comprising (i) a polymeric film having a thickness of not more than 150 μm and formed from an ionomer of an olefin-vinyl carboxylic acid copolymer, (ii) on a first side of said polymeric film a cross-linked polyurethane layer comprising the crosslinking reaction product of a polyurethane containing acid groups and a crosslinker and (iii) on a second side of said polymeric film opposite to said first side, an adhesive layer.  
   
   
       2 . Multi-layer sheet according to  claim 1  wherein said polyurethane having acid groups comprises a polycarbonate based polyurethane comprising the reaction product of a polycarbonate polyol or a polycarbonate polyamine and an aliphatic polyisocyanate.  
   
   
       3 . Multi-layer sheet according to  claim 1  wherein the cross-linked polyurethane layer comprises a matting agent having an average particle size of not more than 10 μm.  
   
   
       4 . Multi-layer sheet according to  claim 3  wherein said matting agent comprises silica matting agent.  
   
   
       5 . Multi-layer sheet according to  claim 1  wherein said polymeric film is formed from an ionomer of an ethylene/acrylic acid copolymer or an ethylene/methacrylic acid copolymer.  
   
   
       6 . Multi-layer sheet according to  claim 1  wherein said adhesive layer comprises a normally tacky pressure sensitive adhesive layer.  
   
   
       7 . Multi-layer sheet according to  claim 1  wherein said cross-linker is a polyfunctional aziridine.  
   
   
       8 . Multi-layer sheet according to  claim 1  wherein said polyurethane having acid groups has an acid number of at least 15 mg KOH/g.  
   
   
       9 . A motor vehicle having attached to a door post or window post a multi-layer sheet as defined in  claim 1 .  
   
   
       10 . Method of making a multi-layer sheet comprising the steps of: 
 (a) providing a polymeric film having a thickness of not more than 150 μm and formed from an ionomer of an olefin-vinyl carboxylic acid copolymer;    (b) applying to a first side of said polymeric film a composition comprising a polyurethane containing acid groups and a crosslinker;    (c) applying to a second side of said polymeric film opposite to said first side, an adhesive layer; and    (d) causing cross-linking of the polyurethane layer.    
   
   
       11 . Method according to  claim 10  wherein said composition comprising said polyurethane further comprises a matting agent having an average particle size of not more than 10 μm.  
   
   
       12 . Method according to  claim 10  wherein said composition comprising said polyurethane is aqueous borne.  
   
   
       13 . Multi-layer sheet according to  claim 2  wherein said polymeric film is formed from an ionomer of an ethylene/acrylic acid copolymer or an ethylene/methacrylic acid copolymer.  
   
   
       14 . Multi-layer sheet according to  claim 3  wherein said polymeric film is formed from an ionomer of an ethylene/acrylic acid copolymer or an ethylene/methacrylic acid copolymer.  
   
   
       15 . Multi-layer sheet according to  claim 4  wherein said polymeric film is formed from an ionomer of an ethylene/acrylic acid copolymer or an ethylene/methacrylic acid copolymer.  
   
   
       16 . A motor vehicle having attached to a door post or window post a multi-layer sheet as defined in  claim 2 .  
   
   
       17 . A motor vehicle having attached to a door post or window post a multi-layer sheet as defined in  claim 5 .  
   
   
       18 . A motor vehicle having attached to a door post or window post a multi-layer sheet as defined in  claim 6 .  
   
   
       19 . A motor vehicle having attached to a door post or window post a multi-layer sheet as defined in  claim 7 .  
   
   
       20 . Method according to  claim 10  wherein said composition comprising said polyurethane is aqueous borne.